1. Technical Field
An embodiment of the present invention relates to a turbine and, more particularly, to a turbine including a packing device between the rotor shaft and casing of the turbine and a method of assembling the turbine.
Furthermore, an embodiment of the present invention relates to a sealing assembly and, more particularly, to a sealing assembly installed between the casing and packing device of the turbine.
2. Description of the Related Art
A turbine is a power generation apparatus for converting thermal energy of a fluid, such as high-temperature and high-pressure steam or gas generated by a boiler or steam generator, into rotatory power, that is, mechanical energy, and is an apparatus that may be used to generate electric power by driving an electric generator.
Referring to FIG. 1, a conventional turbine includes a turbine rotor 10 configured to have a plurality of rotating blades 12 mounted on a rotor shaft 11 and a bearing 50 configured to rotatably the rotor shaft to a base stand 20. The plurality of rotating blades is arranged along the passage of a fluid. A plurality of fixing blades (not illustrated) is provided between the plurality of rotating blades and configured to induce thermal energy of a fluid to be converted into rotatory power. In the flow direction of a fluid, a fluid guide 31 is provided on the downstream side.
The conventional turbine further includes a casing 30 configured to accommodate, protect, and support various elements, such as a turbine rotor, and to maintain internal pressure. Both ends of the rotor shaft 11 are extended to the outside of the casing. The bearing 50 is fixed to the base stand 20 outside the casing 30, and rotatably supports the rotor shaft. Since the rotor shaft 11 is extended outside the casing 30, a packing ring 41 is provided between the rotor shaft 11 and the casing 30, thus preventing a fluid from leaking. The packing ring 41 is supported by a support unit 42 fixedly connected to the casing 30.
As indicated by arrows in FIG. 2, if internal pressure in the casing 30 is changed, the casing may be moved. For example, internal pressure may be changed by vacuum pressure generated by a part, such as a condenser included in the casing. In this case, the packing ring 41 fixedly connected to the casing 30 is also moved. In contrast, since the rotor shaft 11 is supported by the base stand 20, the location of the rotor shaft 11 is not changed although the casing 30 is deformed.
As described above, the casing is deformed in response to a change in the internal pressure of the casing, whereas the location of the rotor shaft is not changed. Accordingly, it is necessary to design the packing ring so that the packing ring and the rotor shaft have a clearance by taking into consideration deformation of the casing.
Accordingly, the amount of an internal fluid that leaks from the inside of the casing to the outside of the casing or the amount of an external gas or external fluid that flows from the outside of the casing to the inside of the casing is affected by the size of the clearance. As a result, efficiency of the turbine is influenced.
The conventional turbine is problematic in that the leakage of a fluid within the casing or the introduction of a fluid or gas outside the casing is generated between the packing ring and the rotor shaft because the size of the clearance must be increased by taking into consideration a relative location movement between the packing ring and the casing.